PC Hardware → New Low Power HTPC or Repair Core2Duo?

Currently I am running a HTPC on an old Core2Duo Dell. I am running into my second hard drive failure, unrelated to the Dell.

So that has me wondering, since I am going to be buying a new hard drive at the least, should I put this old girl out to pasture?

Mindless spending I am not above, but would I even see a noticeable difference in power draw to even start to justify the upgrade costs when the Core2Duo meets my needs? If so what is a good mobo/cpu combo to look for (I would like on board hdmi and gigabit)?

"but would I even see a noticeable difference in power draw"

No. core 2 duos were generally 65w tdp chips. Even running 24/7 you aren't going to get enough benefit to justify changing for that reason. I would just stick with what you have as you say it meets your needs.

In general no you would not see a noticeable difference unless you specifically built a system targeted for low-power.

If you targeted a stable board and used integrated graphics (which are more than sufficient for HTPC use) on a third- or fourth-gen low-power i5, with a low-power 2.5" spinning drive (or SSD), and with low-voltage (1.3v) memory you may have a noticeable difference.

The largest gain likely would be from moving to integrated graphics from a discrete video processor (either onboard or separate card). The 3rd & 4th gen Core i5 are also more power efficient, but you would notice a larger benefit by leveraging a low power (T) processor at 45W or less.

My current HTPC uses a first-gen core i5 T processor in an intel mini-itx board. Runs at about 9 watts idle, about 70 watts running all-out, and around 30-50 watts typically depending on video content.